There are machines currently present on the market for making "espresso" coffee which are integrated, in the sense that the water supply necessary for preparing a number of beverages is contained inside said machines: many of these machines are provided with a delivery nozzle which allows both any liquid to be rapidly heated up and foam to be risen in coffee, milk, white coffee, chocolate and the like, by the admission of overheated steam.
The steam delivering nozzles of such machines are usually rather defective in the sense that the simplest types, consisting of simple pipes, are not able to produce dense and plentiful foam, while the most complex ones are more difficult to clean and are significantly more expensive.
In addition to this, the integrated coffee machines deal with rather large quantities of water, thus requiring some time for delivering the steam, and are quite cumbersome.